1 /* 2 * Copyright 2010 Marek Olk <maraeo (at) gmail.com> 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * on the rights to use, copy, modify, merge, publish, distribute, sub 8 * license, and/or sell copies of the Software, and to permit persons to whom 9 * the Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, 19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 21 * USE OR OTHER DEALINGS IN THE SOFTWARE. */ 22 23 /** 24 * @file 25 * Simple slab allocator for equally sized memory allocations. 26 * util_slab_alloc and util_slab_free have time complexity in O(1). 27 * 28 * Good for allocations which have very low lifetime and are allocated 29 * and freed very often. Use a profiler first to know if it's worth using it! 30 * 31 * Candidates: get_transfer 32 * 33 * @author Marek Olk 34 */ 35 36 #ifndef U_SLAB_H 37 #define U_SLAB_H 38 39 #include "os/os_thread.h" 40 41 enum util_slab_threading { 42 UTIL_SLAB_SINGLETHREADED = FALSE, 43 UTIL_SLAB_MULTITHREADED = TRUE 44 }; 45 46 /* The page is an array of blocks (allocations). */ 47 struct util_slab_page { 48 /* The header (linked-list pointers). */ 49 struct util_slab_page *prev, *next; 50 51 /* Memory after the last member is dedicated to the page itself. 52 * The allocated size is always larger than this structure. */ 53 }; 54 55 struct util_slab_mempool { 56 /* Public members. */ 57 void *(*alloc)(struct util_slab_mempool *pool); 58 void (*free)(struct util_slab_mempool *pool, void *ptr); 59 60 /* Private members. */ 61 struct util_slab_block *first_free; 62 63 struct util_slab_page list; 64 65 unsigned block_size; 66 unsigned page_size; 67 unsigned num_blocks; 68 unsigned num_pages; 69 enum util_slab_threading threading; 70 71 pipe_mutex mutex; 72 }; 73 74 void util_slab_create(struct util_slab_mempool *pool, 75 unsigned item_size, 76 unsigned num_blocks, 77 enum util_slab_threading threading); 78 79 void util_slab_destroy(struct util_slab_mempool *pool); 80 81 void util_slab_set_thread_safety(struct util_slab_mempool *pool, 82 enum util_slab_threading threading); 83 84 #define util_slab_alloc(pool) (pool)->alloc(pool) 85 #define util_slab_free(pool, ptr) (pool)->free(pool, ptr) 86 87 #endif 88
